Makeup Exploration

Fiberglass is a strong lightweight material and is used to reinforce many products. Although it is not as strong and stiff as composites based on carbon fibre, it is less brittle, and its raw materials are much cheaper. Applications of fiberglass include,

• Aircraft Boats

• Automobiles

• Bath tubs and enclosures

• Septic tanks

• Water tanks

• Roofing

• Mould making

 

Health and safety

Fiberglass will irritate the eyes, skin, and the respiratory system. Symptoms can include irritation of eyes, skin, nose, throat, breathing difficulty; sore throat, hoarseness and cough. Scientific evidence demonstrates that fiber glass is safe to manufacture, install and use when recommended work practices are followed to reduce temporary mechanical irritation.

 

Respirators

Disposable - approx. £20 and lasts about a month

Reusable – approx. £30 and lasts about 6 months – just need to replacement filters – the black stripe

Full face – filters are on the belt

 

Hand protection

Latex isn’t very good for polyester resin as break down – Nitrile ones is best

 

Eye protection

Always wear googles when working with fibreglass as will cause alot of harm if has contact with the eyes 

 

Protective clothing 

Not necessity but ideally wear loose clothing as if materials spills onto yourself then you will be able to pull clothing away from the skin.

 

 

GRP materials

 

Glass matting – Its strips of glass heated to a high temperature then pulled quickly, and bound together by starch. It doesnt have any liner strength. It comes in many forms, such as;

• Loose chopped strands 

• Woven matting – like a woven fabric, more used in industrial as they have a higher strength. 

• Fine surface tissue/ vale - Act as a finishing layer to cover up the coarse glass pattern. 

• Fibreglass tape and rope - made from high temperature texturized fiberglass yarn with low thermal conductivity. Used when narrow strips of reinforcement is required. 

 

Resin - When producing GRP moulds, unsaturated polyester resings are used. By being unsaturated this means that the resin is capable of being cured from a liquid to a solid state by using a catalyst. There are many different types of these resins, all containing different characterists, which range from strong, hard solids or to more flexible materials when cured. 

 

• Gel coat resin – Is the smooth, hard polyester surface coating of a fibreglass structure. The resin comes pre coloured and will change colour once catalysis is added. Creates a smooth finish and pick up all the texture but Its brittle without being reinforced.

• Lay-up resin – It's a Polyester resin, within the group of synthetic resins, that undergoes polymerization during curing. It has excellent adhesive properties, high strength, good chemical resistance. Fiberglass resin contains styrene, which reacts with the glass fibres in the fiberglass mat, cloth and tissue, softening it so that it is easy to shape and mold around forms. 

 

Other resins may be used for particular work, such as; better resistance to chemicals (furance resin), heat (silicone resins) or to help pick up more detail (epoxy resin).

 

Catalyst – Methyl Ethyl Ketone Peroxide (MEKP), Organic Peroxide. Added to the Gel coat and Lay-up resin to make it cure. It's very corrosive so be careful when using. Other catalysts that can be used are Cyclohexanone-peroxide, which is less reactive but more stable and comes in a paste form. Benzole-peroxide, is very reactive like the MEKP but comes in either a paste or powder form.

 

Fillers - Can be added to liquid resin to provide more thickness. Fibrous fillers, such as chopped glass fibre, can improve the strength or more simply industrial talcom powder can be used. 

 

Polishes and release agents - Carnauba wax is the best polish to use. Be careful of ingredients as it can effect the setting of the gel coat for example Silicone waxes can inhibit the gel coat and also release agents will not dry over a silicone surface. 

Within GRP, polyvinyl alcohol is widely used as its easy to apply, can be diluted and coloured. However it has a low viscosity so will drain off vertical surfaces and is used over non-pourous mould surfaces. Candle wax is very useful when covering undercuts. 

 

Pigments - Pigment can be added throughout the process but usually is used with the gel coat. It used comes in paste forms in many colours. However it can affect the gel time of the resin, black and blue will increase it while others may shorten it. 

 

 

Advantages and disadvantages?

 

It lasts a long time, it can be coloured, shiny or dull. It is low maintenance, anti-magnetic, fire resistant and weatherproof. The materials are reasonably inexpensive and durable allowing it to make many castings from. It can be used as a mold material for baking foam latex and takes less time than a plaster mold. It’s very lightweight and tough, making it easier to handle. 

 

Fillers can be used to add strength and longevity. Adding cab-o-sil to the laminating resin will make it thicker. By adding chopped fibres to the laminating resin will make it stronger. Metallic powders can also be added as fillers. They make a material stronger but also heavier, it adds weight proportionally by volume and will also tint the material to the metallic colour. 

 

Fibre glass is not that flexible, so it’s important to make sure that there isn’t any undercuts, otherwise it could break the mold when paring apart. It needs to be bolted as although the mold will be strong and stiff, it will be thin and especially on a larger mold there will be flexibility. So by bolting the pieces together around the mold flange, the flexibility is reduced and the mold becomes more firm and holds it shape better when casting. This means that the dividing wall needs to be bigger than making a plaster mold, as its important to create a fibreglass flange wide enough for you to bolt the two sections of the mold together and the clay wall will need to be wide aswell.